The objectives of the MBRS program at York College - "Research and Training for Biomedical Career Development" - are to improve and strengthen the research environment and to broaden the scope of biomedical research in the college for two purposes: (1) to improve the research skills and increase the scholarly productivity of the faculty, and (2) to provide the minority students with increased opportunities to acquire the knowledge, expertise and motivation that will (1) direct them towards careers in biomedical research and (b) enable them to successfully compete for positions in graduate and professional schools. To these ends support is requested for 7 projects ina the areas of cell biology, physical chemistry, molecular biology, microbial and molecular genetics, organic chemistry, and sociology. Support is also requested for 14 students who will participate in all phases of the planning and implementation of the research, as well as in the reporting and publication of the results. In project #1, "Electronic Spectroscopy of Simple Porphyrins", excited electronic states of model biological chromophores will be studied. In project #2 "Sequence and Structure Signals for 5SRNA processing in Drosophila melanogaster", mutant RNAs will be produced and analyzed. Project #3 "Studies on the Mechanism of IS2 Transposition" will develop an in vivo transpositional assay by which inter and intramolecular transposition events can be studied. In Project #4, "Exposure to Chronic Community Violence and Its Consequences" the psychological an physical illness effects of this environmental stress will be studied. Project #5, "Ring Expanded 1,3 Dihetero Nucleosides", will investigate stereochemical requirements for antiviral activity by the controlled synthesis of 1,3 dihetero nucleosides and in project #6, "Uniquely Labelled Amino Acids for Protein NMR", 2H, 13C, and 15N labelled amino acids will be synthesized and incorporated into proteins for further study by solution and solid state NMR. Subproject #4 is new to this mBRS proposal. All other subprojects are components of the MBRS grant currently held by York College.